The temperature-dependent fracture strength model for ultra-high temperature ceramics

Breaking down the entire structure of a material implies severing all the bonds between its atoms either by applying work or by heat transfer. Because bond-breaking is indifferent to either means, there is a kind of equivalence between heat energy and strain energy. Based on this equivalence, we assume the existence of a constant maximum storage of energy that includes both the strain energy and the corresponding equivalent heat energy. A temperaturedependent fracture strength model is then developed for ultrahigh temperature ceramics （UHTCs）. Model predictions for UHTCs, HfB2, TiC and ZrB2, are presented and compared with the experimental results. These predictions are found to be largely consistent with experimental results.     

热环境对超高温陶瓷材料抗热震性能的影响

基于超高温陶瓷材料相关材料参数对温度的敏感性,以现有的抗热震断裂评价理论为基础,通过考虑温度对超高温陶瓷材料物理性能的影响,探讨了热震温度范围内热应力衰减系数、表面热传递系数、热冲击初始环境温度等热环境参数对抗热冲击阻力参数、断裂临界温差和断裂临界温度的影响.      

金属基复合材料的强度与损伤分析

用细观计算力学的方法分析了金属基复合材料(MMC)多重损伤与强度的关系,采用唯象的内聚力模型模拟纤维/基体界面的脱粘和采用G-T模型描述韧性基体的损伤.并用上述模型分析了长纤维增强MMC在横向荷载作用下损伤演化的规律,讨论了不同界面性质与材料强度及损伤、破坏模式之间的关系.